This smacks of subliminal advertising, it's not 'done', possibly even illegal, it certainly is in film and television advertising.
There are two sides to a phone call, a caller and a called person, afaik they both hear the same sound.
There are two sides to a phone call, a caller and a called person, afaik they both hear the same sound.
Not necessarily true. Example: when your credit is about to expire, you get a notification that the other side won't hear. Two sides in a call can hear two different sounds.